The invention relates to a manipulation-proof RFID antenna having a security feature.
It is known, especially in multi-layer configurations for proof of manipulation, to provide an intermediate layer, which has a partially varying adherence to the support. This intermediate layer is provided with an adhering layer and applied onto the carrier. If an attempt is made to remove the configuration from the support, this seemingly homogeneous, substantially invisible intermediate layer is damaged in a defined manner due to the varying adhesion regions. The breakage locations can be assembled exactly again only with difficulty, with the result being that any manipulation is evident.
The varying adhesive regions are produced by way of, for example, partially applying a release layer and/or an adhesive layer on the carrier substrate. The varying adhesive regions frequently have defined forms, for example the form of patterns, indicia, lines, letters, geometric shapes, logos, lettering and the like.
A closer inspection reveals generally that the intermediate layer was damaged, that is to say manipulation has occurred. However, if particular care was taken, the damage is often not detectable at first glance.
WO 01/71848 discloses an RFID label having a track that is connected to the RFID components. If manipulation of the tag occurs, this track is damaged. If this track is damaged or interrupted, the antenna ceases to function or its properties are changed.
WO 02/077939 likewise discloses an RFID label having a track that serves to prove manipulation. This track consists of regions made of a metallic conductor and regions of electrically conductive printing ink.